...and you say, "No, that's just your opinion."
...and I say, "Wrong. Surveys show 93% of times Trump is mentioned it's done in a negative light."
I've said nothing about my opinions...
Sure because opinion is no longer in the scope of the discussion as you brought a fact.
If you say "the media is biased against Trump" it's an opinion, if you say "the media is biased against Trump, as this study/survey show" it becomes a fact.
....
It is only at that time that the ignorant person realized the previous statement had empirical support. But he was (or in a reasonably structured debate, should have been) warned of that empirical support by the framing of the original assertion.
As an example of this, suppose you were in a room with nine other people, and such a statement was made. The others all know the facts, but you did not. Reality is reality, it was just you that was ignorant of that.
In the real world, in the realm of science, it does not matter if the reverse is true. Nine could be flat wrong, and one right.